You worry it'll close if you choose a smaller server, but you don't mind your server being instable due to being over capacity (something it's already having issues with, hence asking people not to join)? Like, no matter if the servers goes down due to it being over it's capacity or due to quiting, you still can't use it... Sure it may come back up, but why not join a stable (semi-)big sized instance instead that run smoothly for you and doesn't cause more trouble for the devs?

I mean, you trust the developers to keep things running smoothly, but you don't trust their message to not join because they currently can't...